An actuator automatically opens and closes the covers of a railroad hopper car as the car enters a loading/unloading station. The opening actuator includes a support frame disposed along a railroad track at the station that extends upwardly above the railroad car as it enters the station. An actuator bar is carried by the support frame and extends fore-and-aft of the railroad car adjacent the top thereof. The bar has an inclined unlatching segment for engagement by the latch arms of the covers to raise the arms and release the latches as the car passes thereunder, an intermediate substantially horizontally extending segment and a lifting segment for thereafter opening the covers as the car passes beneath the bar. The closing actuator includes a second support frame disposed along the track that extends upwardly above the car once unloaded. A closing bar is carried by the second frame and extends fore-and-aft of the empty car adjacent the top thereof. The closing bar has a closing segment aligned with the latch arms of the open covers of the car for engaging the arms and closing the covers. A hold-back bar is also carried by the second frame and is spaced apart from and generally level with the closing bar, to maintain the proper overlapping/underlapping relationship of the covers.